Fiji, mundaka, zuma lettuce varieties

ABSTRACT

A new lettuce variety designated FIJI, MUNDAKA, ZUMA is described. FIJI, MUNDAKA, ZUMA are romaine lettuce varieties exhibiting stability and uniformity.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent Application Ser. No. 61/174,739, filed on May 1, 2009, which is hereby incorporated by reference in its entirety.

FIELD

This invention relates to the field of plant breeding. In particular, this invention relates to new lettuce, Lactuca sativa varieties FIJI, MUNDAKA, and ZUMA.

BACKGROUND

Lettuce is an increasingly popular crop. Worldwide lettuce consumption continues to increase. As a result of this demand, there is a continued need for new lettuce varieties. In particular, there is a need for improved romaine lettuce varieties that exhibit improved growth habits, bolting and tip burn tolerance, and disease resistance.

SUMMARY

In order to meet these needs, the present invention is directed to improved romaine lettuce varieties with a medium to light green color and open to cupping growth habit that forms an open to very dense heart, and improved tolerance to bolting and tip burn as well as resistance to tomato bushy stunt virus (tombusvirus), Sclerotinia (S. minor), and corky root (Rhizomonas suberifaciens). In particular, the present invention is directed to lettuce, Lactuca saliva, seed designated as FIJI, MUNDAKA, and ZUMA having ATCC Accession Number X ATCC Accession Number XX, and ATCC Accession Number XXX, respectively. The present invention is further directed to lettuce, Lactuca sativa plants and the lettuce heads produced therefrom produced by growing FIJI, MUNDAKA, and ZUMA lettuce seed.

The present invention is further directed to a Lactuca saliva plant and the lettuce head produced therefrom having all the physiological and morphological characteristics of a Lactuca sativa plant produced by growing FIJI lettuce seed having ATCC Accession Number X. The present invention is further directed to an F₁ hybrid lettuce, Lactuca sativa seed, plants grown from the seed and a head produced therefrom having FIJI as a parent wherein FIJI is grown from FIJI lettuce seed having ATCC Accession Number X.

The present invention is further directed to a Lactuca sativa plant and the lettuce head produced therefrom having all the physiological and morphological characteristics of a Lactuca sativa plant produced by growing MUNDAKA lettuce seed having ATCC Accession Number XX. The present invention is further directed to an F₁ hybrid lettuce, Lactuca sativa seed, plants grown from the seed and a head produced therefrom having MUNDAKA as a parent wherein MUNDAKA is grown from MUNDAKA lettuce seed having ATCC Accession Number XX.

The present invention is further directed to a Lactuca sativa plant and the lettuce head produced therefrom having all the physiological and morphological characteristics of a Lactuca sativa plant produced by growing ZUMA lettuce seed having ATCC Accession Number XXX. The present invention is further directed to an F₁ hybrid lettuce, Lactuca sativa seed, plants grown from the seed and a head produced therefrom having ZUMA as a parent wherein ZUMA is grown from ZUMA lettuce seed having ATCC Accession Number XXX.

The present invention is further directed to pollen and ovules produced by FIJI lettuce plants. The present invention is further directed to tissue culture of FIJI lettuce plants.

The present invention is further directed to pollen and ovules produced by MUNDAKA lettuce plants. The present invention is further directed to tissue culture of MUNDAKA lettuce plants.

The present invention is further directed to pollen and ovules produced by ZUMA lettuce plants. The present invention is further directed to tissue culture of ZUMA lettuce plants.

The present invention is further directed to a method of selecting lettuce plants including: a) growing FIJI lettuce plants wherein the FIJI plants are grown from lettuce seed having ATCC Accession Number X, and b) selecting a plant from step a). The present invention is further directed to lettuce plants and seeds produced by the selected lettuce plants.

The present invention is further directed to a method of selecting lettuce plants including: a) growing MUNDAKA lettuce plants wherein the MUNDAKA plants are grown from lettuce seed having ATCC Accession Number XX, and b) selecting a plant from step a).

The present invention is further directed to lettuce plants and seeds produced by the lettuce plants wherein the lettuce plants are selected by the selection method of the invention.

The present invention is further directed to a method of selecting lettuce plants including: a) growing ZUMA lettuce plants wherein the ZUMA plants are grown from lettuce seed having ATCC Accession Number XXX, and b) selecting a plant from step a). The present invention is further directed to lettuce plants and seeds produced by the selected lettuce plants.

The present invention is further directed to a method of breeding lettuce plants including crossing a lettuce plant with a plant grown from FIJI lettuce seed having ATCC Accession Number X. The present invention is further directed to lettuce plants, heads from the lettuce plants and seeds produced therefrom where the lettuce plant is produced by the breeding method of the invention.

The present invention is further directed to a method of breeding lettuce plants including crossing a lettuce plant with a plant grown from MUNDAKA lettuce seed having ATCC Accession Number XX. The present invention is further directed to lettuce plants, heads from the lettuce plants and seeds produced therefrom where the lettuce plant is produced by the breeding method of the invention.

The present invention is further directed to a method of breeding lettuce plants including crossing a lettuce plant with a plant grown from ZUMA lettuce seed having ATCC Accession Number XXX. The present invention is further directed to lettuce plants, heads from the lettuce plants and seeds produced therefrom where the lettuce plant is produced by the breeding method of the invention.

DETAILED DESCRIPTION

In order to more clearly understand the invention, the following definitions are provided:

Romaine Lettuce: Romaine lettuce is Lactuca sativa L. var. longifolia Lam; also known as Cos. The plant develops in an upright open or upright compact growing habit with coarse textured leaves. The leaves are longer than they are wide, cupping together to form an elongated loose head. Leaf margins are often entire or undulated, rarely frilled. Other leaves range in color from light green to dark green with a heavy midrib. Inner heart leaves are smaller and range from light yellow to light green in color.

Core Length: Core length is the length of the internal lettuce stem. Core length is measured from the base of the cut head to the tip of the core.

Core Diameter: Core diameter is the diameter of the lettuce stem at the base of the cut head.

Romaine Heart: Romaine heart is the densest part of the romaine plant often yellow and light green in color and of succulent texture. The heart is generally enclosed by two to three outer darker green leaves.

Heart Length: Heart length is the length of the vertically sliced lettuce plant as measured from the base of the cut stem to the top leaf margin of the longest outermost leaf that encloses the romaine heart.

Head Length to Core Length Ratio: The ratio of the head length to core length is indicative of the percentage of useable product produced by the lettuce plant.

Plant Diameter: The plant diameter is a measurement across the top of the lettuce plant at its widest point. The measurement of frame diameter is taken from the outermost leaf tip horizontally to the outermost leaf tip.

Head Weight: Head weight is the weight of the marketable lettuce plant, cut and trimmed to market specifications.

Rogueing: Rogueing is the process in lettuce seed production where undesired plants are removed from a variety. The plants are removed because they differ physically from the general desired expressed characteristics of the variety. The differences can be related to size, color, maturity, leaf texture, leaf margins, growth habit, or any other characteristic that distinguishes the plant.

Market Stage: Market stage is the stage when a lettuce plant is ready for commercial lettuce harvest. In the case of a romaine lettuce variety, a romaine plant is at a marketable state when the heart has some density and the head has reached an adequate size and weight.

PIC Type: PIC is an acronym for Paris Island Cos, a specific type and characterization of romaine lettuce. A PIC type romaine refers to an often vigorous growing romaine type with a smooth leaf surface. PIC type romaine varieties are often less heat resistant and faster growing than Florida type romaines.

Florida Type: A Florida type romaine refers to a specific class of romaine varieties with improved heat and bolting resistance, a more savoyed leaf surface, and corky root resistance. This class of romaine is often less vigorous and slower growing than the PIC type.

Sclerotinia: Two species of Sclerotinia infect lettuce in California and cause a disease known as lettuce drop: in coastal growing areas Sclerotinia minor is the primary species of importance, while in other areas S. sclerotiorum is more prevalent. Sclerotinia minor only infects the stems and leaves in contact with the soil. Once infection takes place, the fungus will cause a brown, soft decay that eventually destroys the plant crown tissue. Older leaves then wilt and later the entire plant will wilt and collapse, making it unharvestable. Plant collapse usually occurs when lettuce is near maturity. Profuse amounts of white mycelia and small (up to 0.125 inch or 3 mm), black, hard, resting bodies (sclerotia) form on the outside of the decayed crown.

Sclerotinia sclerotiorum can also infect lower leaves and stems, causing symptoms similar to those of S. minor. In addition, S. sclerotiorum has an aerial spore that can infect any of the upper leaves. Spores usually infect damaged or senescent tissue when the weather is cool and moist. Infection results in a watery, soft rot that is accompanied by white mycelial growth and formation of sclerotia. Sclerotinia sclerotiorum forms sclerotia that are larger (0.25-0.50 inch) than those of S. minor.

Sclerotia of both species enable the pathogens to survive in the soil for 2 to 3 years without susceptible hosts. Wet soil conditions favor disease development of both species. For S. sclerotiorum, cool and moist conditions are necessary for development of the fruiting structure (apothecium) that produces the airborne spores. In California, S. minor does not have a spore-producing stage. Symptoms caused by Sclerotinia species could resemble Verticillium wilt symptoms. The recent use of wider, 80-inch beds for lettuce production may cause lettuce drop from S. minor to be more severe because of increased bed moisture. In addition, the use of wider beds may be allowing S. sclerotiorum to increase in importance in the Salinas and other coastal valleys.

Tomato Bushy Stunt: Lettuce dieback was first observed in California in the mid-1980s, and reports of the disease have increased over the last 10 years. Complete crop losses have occurred in fields of romaine lettuce, and no commercial romaine cultivar has been shown to be resistant to the disease. In the U.S., romaine is a rapidly growing market segment, having increased 68% over the last five years (USDA, 2002). The disease has occurred in commercial fields of some leaf lettuce cultivars; however, symptoms have never been observed on any modern crisphead (iceberg) cultivars. Lettuce dieback is caused by several related tombusviruses including tomato bushy stunt virus (TBSV) and lettuce necrotic stunt virus (LNSV) (Liu et al., 1999; Obermeier et al., 2001). These are soilborne, highly stable, and mechanically transmitted, and have no known vector. The conditions affecting symptom development remain poorly understood. The disease is frequently observed in low-lying areas of fields with a prior history of flooding, suggesting that the virus may be carried in river water and/or that disease symptoms may be associated with increased root stresses such as those presented by excess moisture. No effective cultural or chemical control methods have yet been identified.

Corky Root: The pathogen responsible for corky root is Rhizomonas suberifaciens. CA1 is the most common strain and is publically available from the American Type Culture Collection (ATCC) (Accession No. 49355). Other useful strains include CA# and CA 15. Colonies of R. suberifaceins are initially translucent but later become opaque. The colonies are umbonate, compact colonies, which ultimately become wrinkled and have raised edges on S-medium as described in Van Bruggen, et al. 1990, Host Range of Rhizomonas suberifaciens, the causal agent of corky root of lettuce. Plant Disease, 74:581-584.

R. Suberifaciens is an aerobic bacterium, ranging in morphology from small (0.6-1-4μ by 0.3-0.6μ) rods with one lateral flagellum to long filaments. According to the potassium hydroxide (KOH) stringiness test, the bacteria seemed gram-positive, but with Hucker's gram-stain the bacteria stain gram-negative.

The type strain CA1 and other equivalent strains are publically available in the Salinas Valley of California growing in the soil of lettuce fields. It is quite common and can be isolated using the baiting procedure described in Example 4 of the Van Bruggen article (1990). Strains are conveniently available from Dr. Ariena Van Bruggen at the University of California, Davis.

Early symptoms of corky root are yellow bands on tap and lateral roots of lettuce seedlings. These yellow areas gradually expand, taking on a green-brown color and developing cracks and rough areas on the surface of the root. As disease severity increases, the entire taproot may become brown, severely cracked, and nonfunctional; the feeder root system will also be reduced and damaged. At this point, roots are very brittle and easily break off when examined. Corky root may cause internal discoloration of the root. When the root is severely diseased, aboveground symptoms consist of wilting during warm temperatures, stunting of plants, and general poor and uneven growth. Corky root symptoms could be confused with ammonium toxicity, which causes a brick-red discoloration of the central portion of the root and wilting of lettuce foliage.

The corky root bacterium, Rhizomonas suberifaciens, is a soilborne pathogen that is prevalent in most coastal lettuce growing areas but may not be present in inland regions. Corky root affects both leaf and head lettuce varieties. Disease is typically more severe when soil temperatures are warmer. Corky root is worse in fields where lettuce is grown consecutively. High soil nitrate levels can increase disease severity.

Resistance to TBSV refers to a level of resistance in a lettuce variety as measured by visual symptoms. Resistance is deemed present when symptoms are not present in at least 80% of a lettuce variety when exposed to TBSV. For example, a variety is said to be resistant to TBSV if at least 80 plants out of 100 plants do not exhibit TBSV symptoms when the field is exposed to the virus.

Resistance to Sclerotinia minor refers to leaf drop of lettuce or lettuce drop. A variety is considered resistant when greater than 80% of a planted variety is not visibly infected in a field harboring S. Minor under weather conditions in which susceptible varieties, e.g., King Henry, exhibit about 90% infection. In a field of 100 plants, 90% infection means that at least 90 plants are infected with S. Minor and exhibit lettuce drop symptoms. Similarly, plants would be considered resistant if 80 plants or more in the same field do not exhibit lettuce leaf drop symptoms.

Resistance to corky root is determined by PCR marker analysis. PCR marker analysis is performed to determine the presence of the recessive cor gene. 10 plants of each test line are screened with a marker. If all 10 plants of the test variety show the presence of the gene the variety is designated as resistant. If all 10 plants tested show the absence of the gene the variety is indentified as susceptible. Such tests are performed commercially by California Seed & Plant Laboratory, Elverta, Calif.

Taking into account these definitions, the present invention is directed to seeds of the lettuce variety FIJI, MUNDAKA, ZUMA, plants produced by growing FIJI, MUNDAKA, ZUMA lettuce seeds, head isolated or harvested from the plants, one or more plants selected from a collection of FIJI, MUNDAKA, ZUMA plants and seeds derived or produced therefrom; plants produced by crossing a lettuce plant with a FIJI, MUNDAKA, ZUMA lettuce plant and seeds derived or produced therefrom.

Origin and Breeding History of the Variety FIJI, MUNDAKA, ZUMA

FIJI: FIJI is a tall and heavy PIC type romaine variety that is adapted to the coastal production regions of California. This variety is distinct due to its combined disease and physiological resistances. FIJI has a unique and valuable resistant resistance package, as it is resistant to TBSV, Sclerotinia and corky root, three very problematic diseases found throughout the Salinas Valley of California. In addition to these disease resistances, FIJI is also resistant to the physiological problems associated with internal tip burn and fringe burn.

FIJI is a romaine lettuce variety developed from a hand pollinated cross of the iceberg variety PRO 1432, a Progeny Advanced Genetics breeding line and the commercial romaine cultivar Frontier, available from Central Valley Seed. The two parental varieties were selected for their specific disease and physiological resistances, and their respective yield potential.

PRO 1432 is a slightly savoyed and slow growing romaine variety with excellent densely formed heavy hearts and a low core. PRO 1432 is resistant to TBSV, Sclerotinia, and segregates for ‘cor’, a marker associated with the presence of the recessive ‘cor’ gene which is responsible for corky root resistance. PRO 1432 is however, highly susceptible to the physiological problems of internal tip burn and fringe burn. These two physiological issues are so significant in the market that the PRO 1432 variety is not commercially viable.

Frontier, the pollen donating parent, was selected for its smooth PIC type leaf texture, its open and slow growth habit, and its tip burn and fringe burn resistance.

The single seed descent method was utilized. This is a well known method of plant breeding. See, for example, Heredity (1975) 35, 211-219.

A cross was made of the Progeny Advanced Genetics breeding line PRO 1432, designated as PSJV043137, and the Central Valley Seed variety Frontier designated as PSJV043131, in a summer research seed production field in the San Joaquin Valley. The F1 seed was harvested in the fall of Year 1 and designated as PSJV043137×PSJV043131.

In late October of Year 1, forty F1 seeds of PSJV043137×PSJV043131 were planted in a green house facility in San Juan Bautista, Calif., designated as line number PSJB043650. At market maturity all apparent self-pollinated plants were removed and the remaining F1 plants were allowed to self-pollinate, the F2 seed was harvested in bulk in late April of Year 2. The seed was cleaned, processed, blended, and prepared for planting.

Two hundred random F2 seeds of line number PSJB043650 were planted in a research seed production field and redesignated as PSJV053832. Segregation amongst the F2 population was noted and all plants were allowed to self-pollinate and produce seed. The F3 seed from each plant were harvested and packaged individually in the fall of Year 2. One seed from each package (plant) was removed and placed in an envelope and designated as PAUS054543. This seed was again in a research production field in Australia in October of Year 2. The production field was observed and segregation for phenotype and maturity was again evident and noted. All plants were allowed to self-pollinate and produce seed. F4 seed from 100 individual plants were harvested, cleaned and packaged individually prior to processing.

The 100 F4 lines, all from nonselected single F3 plants of the pedigree PSJV043137×PSJV043131 were processed in the summer of Year 2. A trial was prepared containing each of the 100 F4 individual lines of the designated pedigree, and an additional 200 lines from different pedigrees, using the parent varieties and susceptible and resistant standard varieties as checks for the multiple diseases. A research trial was planted in the Salinas Valley, Calif. in spring of Year 4 in a field known to be infected with TBSV. The trial was evaluated in summer Year 4. All F4 lines were evaluated based on phenotypic uniformity, improved size, improved weight, and improved tolerances to tip burn and fringe burn as compared to the parent and check or control varieties. The F4 lines were also rated on their resistance to TBSV. After multiple evaluations of the trial, 1 F4 line of this pedigree was selected as out performing the parent varieties, its sibs, and the majority of other lines in the trial for the designated traits. PAUS 054543-49 W/S was the single F4 lines advanced from this trial.

PAUS 054543-49 W/S, along with its parent lines, check varieties, and multiple other advanced lines from multiple pedigrees were trialed in 5 additional fields between July of Year 4 and May of Year 5. Three of the five fields were known to harbor TBSV, and two of the fields were known to harbor Sclerotinia. The F4 lines were screened for resistance to the diseases present, as well as tip burn and fringe burn. Yield traits such as weight, core length, plant height and heart density were also evaluated. PAUS 054543-49 W/S continued to be resistant to TBSV and showed resistance to Sclerotinia in all trials, while being free of the symptoms associated with tip and fringe burn. This line also rated higher than most of its sibs for the yield traits measured. PAUS 054543-49 W/S was one of the 12 F4 lines advanced for further study.

Simultaneously with the trialing program, seed from these 12 lines were also being increased. A sample of the remnant F4 seed from PAUS 054543-49 W/S, designated as PSJV086279 was planted in a research seed production field in May of Year 5. The block contained roughly 200 plants, which were rogued for phenotype and maturity at various stages of growth. All off-types and variants were removed. The remaining plants in the block were allowed to self-pollinate, and the F5 seed from the block was harvested en masse.

The harvested F5 seed was cleaned, processed and identified as PX 464. Two trials of the F5 PX 464 containing roughly 300 plants each were planted in November of Year 5 in Yuma, Ariz. to verify uniformity and plant type. Evaluations of the trials were conducted in February of Year 6, where they were noted as uniform and free of variants.

A portion of the F5 seed designated PX 464 was also shipped to Chile for an additional seed increase in September of Year 5. Roughly 50,000 plants of PX 464 were observed at multiple stages of growth during the seed production, where it was noted to be uniform and free of variants. The F6 seed of PX 464 was harvested in March of Year 6. The F5 stock seed was again used to conduct an additional increase of PX 464 in a Year 5 commercial seed production crop grown in the San Joaquin Valley. PX 464 was designated Fiji.

As evaluated in multiple seed production fields and commercial plantings plants produced from seed from the variety FIJI have been uniform and stable without variants.

MUNDAKA: MUNDAKA is a tall and heavy PIC type romaine variety that forms large heavy hearts and is adapted to the coastal production regions of California. This variety is distinct due to its combined disease and physiological resistances. MUNDAKA has a unique and valuable resistant resistance package, as it is resistant to TBSV, Sclerotinia and corky root, three very problematic diseases found throughout the Salinas Valley of California. In addition to these disease resistances, MUNDAKA is also resistant to the physiological problems associated with internal tip burn and fringe burn.

MUNDAKA is a romaine lettuce variety developed from a hand pollinated cross of the iceberg variety PRO 1432, a Progeny Advanced Genetics proprietary breeding line and the commercial romaine cultivar Avalanche, also a Progeny Advanced Genetics variety. The two parental varieties were selected for their specific disease and physiological resistances, and their respective yield potential.

PRO 1432 is a slightly savoyed and slow growing romaine variety with excellent densely formed heavy hearts and a low core. PRO 1432 is resistant to TBSV, Sclerotinia, and segregates for ‘cor’, a marker associated with the presence of the recessive ‘cor’ gene which is responsible for corky root resistance. PRO 1432 is however, highly susceptible to the physiological problems of internal tip burn and fringe burn. These two physiological issues are so significant in the market that the variety is not commercially viable.

Avalanche, the pollen donating parent, was selected for its smooth PIC type leaf texture, its tall and vigorous growth habit, its densely formed and heavy hearts, and its tip burn and fringe burn resistance. Avalanche is also resistant to corky root rot, as indicated by the presence of the ‘cor’ gene.

The cross between PRO 1432 and Avalanche was made in Year 1. A large and open growing romaine variety well adapted to the coastal lettuce production regions of California was developed using the single seed descent breeding method. Through extensive field trialing and screenings MUNDAKA has demonstrated resistance to TBSV, Sclerotinia, corky root, tip burn and fringe burn.

A cross was made of the Progeny breeding line PRO 1432, designated as PSJV043137 and, the Progeny variety Avalanche designated PSJV043138 in a summer seed production field in San Joaquin Valley, Calif. The F1 seed was harvested in the fall of Year 1 and designated as PSJV043137×PSJV043138.

In late October of Year 1, forty F1 seeds of PSJV043137×PSJV043138 were planted in a green house facility in San Juan Bautista, Calif., and designated PSJB043659. At market maturity all apparent self-pollinated plants were removed and the remaining F1 plants were allowed to self-pollinate. The F2 seed was harvested in bulk in late April of Year 2. The seed was cleaned, processed, blended, and prepared for planting.

Two hundred random F2 seeds of line number PSJB043659 were planted in a summer research seed production field and redesignated as PSJV053890. Segregation amongst the F2 population was noted and all plants were allowed to self-pollinate and produce seed. The F3 seed from each plant was harvested and packaged individually in the fall of Year 2. One seed from each package (plant) was removed and placed in one envelope and designated as PAUS054549. The seed was planted again in a research production field in Australia in October of Year 2. Segregation for phenotype and maturity was again evident and noted, and all plants were allowed to self-pollinate and produce seed. F4 seed from 100 individual plants was harvested, cleaned and packaged individually. The packets were processed.

The 100 F4 lines, all from nonselected single F3 plants of the pedigree PSJV043137×PSJV043138 were processed in the summer of Year 2. A trial was prepared containing each of the 100 F4 individual lines of the designated pedigree, and an additional 200 lines from different pedigrees, using the parent varieties and susceptible and resistant standard varieties as checks for the multiple diseases. A research trial was planted in the Salinas Valley in spring of Year 4 in a field known to be infected with TBSV. The trial was evaluated in summer of Year 4. All F4 lines were evaluated based on phenotypic uniformity, improved size, improved weight, and improved tolerances to tip burn and fringe burn when compared to the parent and check varieties. The F4 lines were also rated on their resistance to TBSV. After multiple evaluations of the trial, 12 F4 lines of this pedigree were selected as they outperformed the parent varieties, its sibs, and the majority of other lines in the trial for the designated traits. PAUS 054549-8 W/S was among the 12 F4 lines advanced.

The 12 F4 lines of this pedigree, along with their parent lines, check varieties, and multiple other advanced lines from multiple pedigrees were trialed in 5 additional fields between July of Year 4 and May of Year 5. Three of the five fields were known to harbor TBSV, and two of the fields were known to harbor Sclerotinia. The F4 lines were screened for resistance to the diseases present, as well as tip burn and fringe burn. Yield traits such as weight, core length, plant height and heart density were also evaluated. PAUS 054549-8 W/S continued to be resistant to TBSV and showed resistance to Sclerotinia in all trials, while being free of the symptoms associated with tip and fringe burn. This line also rated higher than most of its sibs for the yield traits measured.

Simultaneously with the trialing program, seed from 12 F4 lines were also increased. A sample of the remnant F4 seed from PAUS 054549-8 W/S, designated as PSJV086287 was planted in a research seed production field in May of Year 5. The block contained roughly 200 plants, which were rogued for phenotype and maturity at various stages of growth, all off-types and variants were removed. The remaining plants in the block were allowed to self-pollinate, and the F5 seed from the block was harvested en masse.

The F5 seed harvested were cleaned, processed and identified as PX 465. Two trials of the F5 PX 465 containing roughly 300 plants each were planted in November of Year 5 in Yuma, Ariz. to verify uniformity and plant type. Evaluations of the trials were conducted in February of Year 6, where they were noted as uniform and free of variants.

A portion of the F5 seed designated PX 465 was also shipped to Chile for an additional seed increase in September of Year 5. Roughly 50,000 plants of PX 465 were observed at multiple stages of growth during the seed production, where it was noted to be uniform and free of variants. The F6 seed of PX 465 was harvested in March of Year 6. The F5 stock seed was again used to conduct an additional increase of PX 465 in a Year 5 commercial seed production crop grown in the San Joaquin Valley. PX 465 was designated Mundaka.

As evaluated in multiple seed production fields and commercial plantings the variety MUNDAKA has been uniform and stable without variants.

ZUMA: ZUMA is a tall and heavy PIC type romaine variety that forms dense heavy hearts and is adapted to the coastal production regions of California. This variety is distinct and unique to all other romaine lettuce varieties due to its combined disease and physiological resistances. ZUMA has a unique and valuable resistant resistance package, as it is resistant to TBSV, Sclerotinia and corky root, three very problematic diseases found throughout the Salinas Valley of California. In addition to these disease resistances, ZUMA is also resistant to the physiological problems associated with internal tip burn and fringe burn.

ZUMA is a romaine lettuce variety developed from a hand pollinated cross of the iceberg variety PRO 1432, a Progeny Advanced Genetics breeding line and the commercial romaine cultivar Avalanche, also a Progeny Advanced Genetics variety. The two parental varieties were selected for their specific disease and physiological resistances, and their respective yield potential.

A cross was made of the Progeny breeding line PRO 1432, designated as PSJV043137 and, the Progeny variety Avalanche designated PSJV043138 in Year 1 in San Joaquin Valley, Calif. The F1 seed was harvested in the fall of Year 1 and designated as PSJV043137×PSJV043138.

In late October of Year 1, forty F1 seeds of PSJV043137×PSJV043138 were planted in a green house facility in San Juan Bautista, Calif., and designated PSJB043659. At market maturity all apparent self-pollinated plants were removed and the remaining F1 plants were allowed to self-pollinate. The F2 seed were harvested in bulk in late April of Year 2. The seed was cleaned, processed, blended, and prepared for planting.

Two hundred random F2 seeds of line number PSJB043659 were planted in a summer research seed production field and redesignated as PSJV053890. Segregation amongst the F2 population was noted and all plants were allowed to self-pollinate and produce seed. The F3 seed from each plant were harvested and packaged individually in the fall of Year 2. One seed from each package (plant) was removed and placed in one envelope and designated as PAUS054549, and planted again in a research production field in Australia in October of Year 2. Segregation for phenotype and maturity was again evident and noted, and all plants were allowed to self-pollinate and produce seed. F4 seed from 100 individual plants was harvested, cleaned and packaged individually. The packets were then processed.

The 100 F4 lines, all from nonselected single F3 plants of the pedigree PSJV043137×PSJV043138 were processed in the summer of Year 2. A trial was prepared containing each of the 100 F4 individual lines of the designated pedigree, and an additional 200 lines from different pedigrees, using the parent varieties and susceptible and resistant standard varieties as checks for the multiple diseases. A research trial was planted in the Salinas Valley in spring of Year 4 in a field known to be infected with TBSV. The trial was evaluated in summer of Year 4. All F4 lines were evaluated based on phenotypic uniformity, improved size, improved weight, and improved tolerances to tip burn and fringe burn when compared to the parent and check varieties. The F4 lines were also rated on their resistance to TBSV. After multiple evaluations of the trial, 12 F4 lines of this pedigree were selected as they outperformed the parent varieties, its sibs, and the majority of other lines in the trial for the designated traits. PAUS 054549-34 B/S was among the 12 F4 lines advanced.

The 12 F4 lines of this pedigree, along with their parent lines, check varieties, and multiple other advanced lines from multiple pedigrees were trialed in 5 additional fields between July of Year 4 and May of Year 5. Three of the five fields were known to harbor TBSV, and two of the fields were known to harbor Sclerotinia. The F4 lines were screened for resistance to the diseases present, as well as tip burn and fringe burn. Yield traits such as weight, core length, plant height and heart density were also evaluated. PAUS 054549-34 B/S continued to be resistant to TBSV and showed resistance to Sclerotinia in all trials, while being free of the symptoms associated with tip and fringe burn. This line also rated higher than most of its sibs for the yield traits measured.

Simultaneously with the trialing program, seed from these 12 lines were also being increased. A sample of the remnant F4 seed from PAUS 054549-34 B/S, designated as PSJV086291 was planted in a research seed production field in May of Year 5. The block contained roughly 200 plants, which were rogued for phenotype and maturity at various stages of growth, all off-types and variants were removed. The remaining plants in the block were allowed to self-pollinate, and the F5 seed from the block was harvested en masse.

The F5 seed harvested was immediately cleaned, processed and identified as PX 466. Two trials of the F5 PX 466 containing roughly 300 plants each were planted in November of Year 5 in Yuma, Ariz. to verify uniformity and plant type. Evaluations of the trials were conducted in February of Year 6, where they were noted as uniform and free of variants.

A portion of the F5 seed designated PX 466 was also shipped to Chile for an additional seed increase in September of Year 5. Roughly 50,000 plants of PX 466 were observed at multiple stages of growth during the seed production, where it was noted to be uniform and free of variants. The F6 seed of PX 466 was harvested in March of Year 6. The F5 stock seed was again used to conduct an additional increase of PX 466 in a Year 5 commercial seed production crop grown in the San Joaquin Valley. PX 466 was designated Zuma.

As evaluated in multiple seed production fields and commercial plantings the F5 generation of seed from the variety ZUMA has been uniform and stable without variants.

Breeding and Selection

The present invention is further directed to the use of FIJI, MUNDAKA, ZUMA lettuce in breeding and selection of new varieties.

A. Breeding

In lettuce breeding, lines are selected for certain desired appropriate characteristics. For example, one line may be selected for bolt tolerance in the fall growing conditions of the desert production locations of California and Arizona or for resistance to viruses such as TBSV, Sclerotinia or corky root. Another line may be selected for the size, color and texture of the lettuce head. Crosses are made, for example, to produce a medium to light green, tip burn resistant romaine lettuce with improved texture, and size for spring and summer harvest in the Salinas Valley of California.

To optimize crossing, it is important to note that lettuce is an obligate self-pollinating species. This means that the pollen is shed before stigma emergence, assuring 100% self-fertilization. Since each lettuce flower is an aggregate of about 10-20 individual florets (typical of the Compositae family), manual removal of the anther tubes containing the pollen is performed by procedures well known in the art of lettuce breeding.

The manual removal of anther tubes, though an effective means to ensure the removal of all self-pollinating possibilities, is very tedious and time consuming when a large number of crosses are to be made. The breeders have therefore adapted a well documented and modified method of making crosses more efficiently using these methods. This particular cross was made by first misting the designated male flowers to wash the pollen off prior to fertilization. This process of misting is a proven and effective means of pollen removal that assures crossing or hybridization. About 60-90 minutes past sunrise, flowers to be used for crossings are selected. The basis for selection are open flowers, with the stigma emerged and the pollen visibly attached to the single stigma (about 10-20 stigma). Using 3-4 pumps of water from a regular spray bottle, the pollen is washed off with enough pressure to dislodge the pollen grains, but not enough to damage the style. Excess water is dried off with clean paper towels. About 30 minutes later, the styles should spring back up and the two lobes of the stigma are visibly open in a “V” shape. Pollen from another variety or donor parent is then introduced by gently rubbing the stigma and style of the donor parent to the maternal parent. Tags with the pertinent information on date and pedigree are then secured to the flowers in order to keep track.

About 3 weeks after pollination, seeds are harvested when the involucre have matured. The seeds are eventually sown and in the presence of markers such as leaf color or leaf margins, the selfed or maternal seedlings or plants are identified. Generally, there are no visible markers and breeders must wait until the F₂ generations when expected segregation patterns for the genetic character of interest can be followed. This latter situation mandates a lengthy wait to determine if hybrids are produced. Two relevant references teaching methods for out crossing lettuce are: (1) Ryder, E. J. and A. S. Johnson. 1974. Mist depollination of lettuce flowers. Hortscience 9:584; and (2) Nagata, R. T. 1992. Clip and Wash Method of Emasculation for Lettuce. Hortscience 27(8):907-908 both of which are hereby incorporated by reference in their entirety for the purpose of providing details on the techniques well known in the art. In the present invention, Para Cos and Frontier Cos were crossed.

B. Selection

In addition to crossing, selection may be used to identify and isolate new lettuce lines. In lettuce selection, lettuce seeds are planted, the plants are grown and single plant selections are made of plants with desired characteristics. Such characteristics may include improved head and frame size, deeper or darker green leaf color, etc. Seed from the single plant selections are harvested, separated from seeds of the other plants in the field and re-planted. The plants from the selected seed are monitored to determine if they exhibit the desired characteristics of the originally selected line. Selection work is continued over multiple generations to increase the uniformity of the new line.

C. Deposit Information

Applicants have made available to the public without restriction a deposit of at least 2500 seeds of lettuce variety FIJI with the American Type Culture Collection (ATCC), P.O. Box 1549, MANASSAS, VA 20108 USA, with a deposit on (Date) which has been assigned ATCC number X.

The deposit will be maintained in the ATCC depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if a deposit becomes nonviable during that period.

Applicants have made available to the public without restriction a deposit of at least 2500 seeds of lettuce variety MUNDAKA with the American Type Culture Collection (ATCC), P.O. Box 1549, MANASSAS, VA 20108 USA, with a deposit on (Date) which has been assigned ATCC number XX.

The deposit will be maintained in the ATCC depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if a deposit becomes nonviable during that period.

Applicants have made available to the public without restriction a deposit of at least 2500 seeds of lettuce variety ZUMA with the American Type Culture Collection (ATCC), P.O. Box 1549, MANASSAS, VA 20108 USA, with a deposit on (Date) which has been assigned ATCC number XXX.

The deposit will be maintained in the ATCC depository, which is a public depository, for a period of 30 years, or 5 years after the most recent request, or for the effective life of the patent, whichever is longer, and will be replaced if a deposit becomes nonviable during that period.

This invention will be better understood by reference to the following non-limiting Examples.

EXAMPLES Example 1 General Trialing Method

I. Set Up

The following steps illustrate the general trialing method of the invention.

A trial is set up to compare one or more lines. Parental lines and related varieties are identified.

Primary slots are identified.

Accession lines are located and purchased/obtained from seed dealers or growers.

All varieties are assigned a number to maintain integrity and anonymity.

Trials are set up in with all necessary varieties. Variety arrangement for trial is diagramed.

II. Planting

Commercial plantings are located by contacting commercial growers during the planting slot recommended for the variety.

A field is located during commercial planting and the necessary rows and area is marked off.

Varieties are planted according to a diagram, generally in 100 foot ranges.

All varieties are planted in same manner to mimic the planting of the commercial variety as closely as possible.

A trial map is drawn diagramming the trial, the trial location in the field and directions to the field.

III. Maintenance

All tested varieties are treated identically. Plants are watered, fertilized, and treated to control pests in the same manner as other lettuce plants in the commercial field.

The trial is thinned to separate the plants for optimum growth.

IV. Evaluation

Evaluations are done as near to the time of the commercial harvest as possible.

The evaluation is conducted “blindly”. The evaluator(s) do not have the key to the trial at the time of evaluation.

24 heads of each variety are evaluated.

a. The frame diameter of 24 random plants are measured to the nearest cm.

b. 24 mature heads of each variety are cut to the cap leaf.

c. The heads are carried to an adequate work station.

d. The following measurements are then conducted and recorded:

-   -   1. Each head is weighed to the nearest gram.     -   2. The core diameter of each head is measured to the nearest mm.     -   3. The heads are then sliced into halves, discarding 1 half.     -   4. The core lengths (from the cut stem to the core tip) are         measured to the nearest mm.     -   5. The plant length (from the cut stem to the cap leaf) is         measured to the nearest mm.     -   6. The plant diameter (at its widest point) is measured to the         nearest mm.     -   7. The heart length is measured to the nearest mm.     -   8. The ideal maturity or harvest date is then estimated based on         the solidity of the head, the core length and any other         physiological characteristics present.     -   9. The leaf color is documented using the Munsell Color Charts         for Plant Tissue.

e. From these measurements, an Excel program is used to calculate the averages, the standard deviations and the T-Tests for the compared varieties.

Example 2 Comparative Analysis

Following the procedures of Example 1, FIJI, MUNDAKA, ZUMA romaine lettuce were compared to various other varieties. Comparative data was obtained and analyzed for different romaine lettuce lines. Core length, plant length, head weight and frame diameter as provided in the definitions section above were compared. The results are shown in Tables 1-9. Tables 1-3 show a comparison of Fiji to Sun Belt. Sun Belt is a standard commercial variety. Tables 4-6 show a comparison of Mundaka to Sun Belt. Tables 7-9 show a comparison of Zuma to Sun Belt.

FIJI, MUNDAKA, ZUMA are distinct romaine lettuce varieties with a medium to light green color and open to cupping growth habit compared to similar varieties. These varieties are slow to medium growing and form an open to very dense and heavy hearts.

The most distinguishing characteristics of these varieties are unique multiple resistances. FIJI, MUNDAKA, ZUMA are resistant to the Tombusvirus known as TBSV, Sclerotinia and corky root.

TABLE 1 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Fiji Sun Belt Fiji Sun Belt Fiji Sun Belt Fiji Sun Belt 1 55 40 225 340 800 900 330 325 2 50 40 230 345 758 925 330 330 3 40 45 245 330 780 936 345 330 4 45 35 230 325 900 987 320 325 5 50 40 245 330 865 852 340 325 6 50 45 245 340 900 852 340 330 7 55 40 250 345 925 896 325 335 8 50 40 250 345 962 845 300 300 9 50 45 265 345 875 924 325 325 10 55 40 250 325 864 968 345 360 11 50 30 255 335 825 923 345 340 12 50 30 260 345 831 956 305 320 13 50 25 235 340 902 987 330 325 14 45 25 245 240 905 967 325 320 15 45 35 265 345 853 983 325 320 16 45 40 260 345 812 925 330 320 17 45 40 255 350 897 900 345 325 18 45 40 250 325 813 901 325 320 19 45 45 255 335 850 956 340 320 20 50 40 254 340 864 945 300 335 Average 48.5 38.0 248.5 333.5 859.1 926.4 328.5 326.5 Stan dev 4.01E+00 6.16E+00 1.13E+01 2.33E+01 5.15E+01 4.40E+01 1.42E+01 1.14E+01 T test 1.65E−07 3.21E−17 7.35E−05 6.25E−01 Probability % 100.00 100.00 99.99 37.50 % −27.6 25.5 7.3 −0.6 Difference Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 2 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Fiji Sun Belt Fiji Sun Belt Fiji Sun Belt Fiji Sun Belt 1 30 20 280 325 700 800 325 295 2 35 20 285 300 756 852 300 290 3 35 25 275 300 825 698 300 285 4 35 25 260 330 845 654 315 300 5 30 25 285 320 823 678 295 300 6 30 20 280 310 851 752 285 325 7 35 25 280 305 702 632 270 310 8 35 30 285 300 812 752 270 295 9 40 30 285 300 756 786 315 290 10 35 25 255 300 715 720 300 305 11 30 30 285 305 698 725 305 300 12 30 35 260 310 628 698 275 315 13 35 30 275 295 700 621 305 305 14 35 30 285 305 725 715 300 300 15 20 25 265 290 768 728 295 300 16 20 20 285 300 800 719 305 295 17 25 25 280 300 812 690 305 300 18 30 25 290 310 758 735 305 315 19 20 30 275 300 742 748 310 290 20 25 35 270 295 812 714 300 285 Average 30.5 26.5 277.0 305.0 761.4 720.9 299.0 300.0 Stan dev 5.83E+00 4.62E+00 1.01E+01 1.01E+01 6.02E+01 5.47E+01 1.45E+01 1.04E+01 T test 2.11E−02 1.14E−10 3.18E−02 8.03E−01 Probability % 97.89 100.00 96.82 19.69 % Difference −15.1 9.2 −5.6 0.3 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 3 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Fiji Sun Belt Fiji Sun Belt Fiji Sun Belt Fiji Sun Belt 1 70 65 255 295 854 654 325 325 2 75 60 250 295 823 625 300 300 3 70 55 255 280 712 724 300 300 4 50 50 260 305 789 765 300 310 5 75 50 250 300 756 805 305 315 6 70 65 275 300 714 723 320 300 7 65 65 280 305 736 654 310 285 8 50 65 255 310 725 628 305 295 9 65 50 250 295 700 648 295 280 10 70 50 260 280 698 659 295 315 11 50 65 270 310 658 756 300 300 12 50 60 270 285 623 698 300 300 13 75 60 270 290 715 741 315 285 14 45 55 250 285 725 721 300 290 15 55 50 250 280 758 695 305 305 16 55 65 300 285 769 632 300 325 17 65 50 275 275 800 754 300 310 18 70 65 275 300 812 798 300 295 19 45 60 250 310 745 654 300 280 20 60 65 250 325 798 669 295 315 Average 61.5 58.5 262.5 295.5 745.5 700.2 303.5 301.5 Stan dev 1.05E+01 6.51E+00 1.38E+01 1.31E+01 5.69E+01 5.68E+01 8.13E+00 1.36E+01 T test 2.85E−01 2.35E−09 1.60E−02 5.75E−01 Probability % 71.48 100.00 98.40 42.47 % Difference −5.1 11.2 −6.5 −0.7 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 4 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Mundaka Sun Belt Mundaka Sun Belt Mundaka Sun Belt Mundaka Sun Belt 1 35 40 325 340 1056 900 300 325 2 35 40 325 345 1152 925 300 330 3 35 45 325 330 1069 936 325 330 4 40 35 320 325 1025 987 295 325 5 35 40 325 330 1156 852 295 325 6 45 45 320 340 1145 852 290 330 7 45 40 305 345 1125 896 290 335 8 45 40 315 345 1002 845 290 300 9 50 45 305 345 998 924 300 325 10 35 40 325 325 965 968 290 360 11 50 30 325 335 1025 923 295 340 12 50 30 300 345 1125 956 209 320 13 50 25 325 340 1135 987 209 325 14 45 25 330 240 1201 967 325 320 15 50 35 325 345 1195 983 325 320 16 50 40 325 345 1098 925 300 320 17 35 40 310 350 1125 900 320 325 18 35 40 325 325 1096 901 325 320 19 50 45 320 335 1156 956 300 320 20 55 40 315 340 1154 945 300 335 Average 43.5 38.0 319.5 333.5 1100.2 926.4 294.2 326.5 Stan dev 7.09E+00 6.16E+00 8.41E+00 2.33E+01 6.83E+01 4.40E+01 3.18E+01 1.14E+01 T test 1.26E−02 1.59E−02 1.16E−11 1.22E−04 Probability % 98.74 98.41 100.00 99.99 % Difference −14.5 4.2 −18.8 9.9 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 5 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Mundaka Sun Belt Mundaka Sun Belt Mundaka Sun Belt Mundaka Sun Belt 1 35 20 300 325 860 800 285 295 2 35 20 295 300 895 852 290 290 3 35 25 290 300 905 698 290 285 4 30 25 285 330 798 654 290 300 5 45 25 285 320 825 678 290 300 6 40 20 280 310 756 752 275 325 7 45 25 275 305 789 632 290 310 8 35 30 285 300 714 752 290 295 9 50 30 275 300 805 786 300 290 10 50 25 270 300 725 720 300 305 11 50 30 285 305 698 725 290 300 12 45 35 285 310 789 698 295 315 13 35 30 290 295 756 621 285 305 14 50 30 300 305 812 715 275 300 15 50 25 300 290 795 728 285 300 16 50 20 300 300 798 719 290 295 17 35 25 285 300 825 690 290 300 18 35 25 275 310 856 735 300 315 19 35 30 270 300 845 748 325 290 20 50 35 265 295 800 714 300 285 Average 41.8 26.5 284.8 305.0 802.3 720.9 291.8 300.0 Stan dev 7.30E+00 4.62E+00 1.08E+01 1.01E+01 5.51E+01 5.47E+01 1.05E+01 1.04E+01 T test 1.58E−09 4.02E−07 3.48E−05 1.72E−02 Probability % 100.00 100.00 100.00 98.28 % Difference −57.5 6.6 −11.3 2.8 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval Confidence 0.042 0.084 0.042 0.026 0.042 0.047 0.042 0.084 Interval

TABLE 6 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Mundaka Sun Belt Mundaka Sun Belt Mundaka Sun Belt Mundaka Sun Belt 1 50 65 275 295 810 654 275 325 2 50 60 275 295 865 625 270 300 3 50 55 285 280 812 724 270 300 4 52 50 275 305 825 765 265 310 5 55 50 270 300 826 805 280 315 6 45 65 270 300 758 723 280 300 7 45 65 265 305 765 654 285 285 8 50 65 280 310 812 628 275 295 9 55 50 280 295 835 648 270 280 10 45 50 295 280 756 659 295 315 11 55 65 255 310 698 756 285 300 12 55 60 275 285 712 698 290 300 13 60 60 280 290 785 741 285 285 14 60 55 280 285 825 721 280 290 15 55 50 280 280 856 695 250 305 16 65 65 295 285 890 632 275 325 17 60 50 270 275 890 754 265 310 18 60 65 285 300 800 798 255 295 19 55 60 290 310 856 654 280 280 20 55 65 280 325 800 669 275 315 Average 53.9 58.5 278.0 295.5 808.8 700.2 275.3 301.5 Stan dev 5.54E+00 6.51E+00 9.65E+00 1.31E+01 5.23E+01 5.68E+01 1.11E+01 1.36E+01 T test 1.98E−02 2.35E−05 2.26E−07 6.23E−08 Probability % 98.02 100.00 100.00 100.00 % Difference 7.9 5.9 −15.5 8.7 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 7 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Zuma Sun Belt Zuma Sun Belt Zuma Sun Belt Zuma Sun Belt 1 35 40 285 340 1100 900 285 325 2 35 40 275 345 1056 925 280 330 3 35 45 275 330 1023 936 280 330 4 40 35 270 325 1054 987 275 325 5 45 40 270 330 965 852 275 325 6 35 45 270 340 1035 852 275 330 7 35 40 275 345 985 896 280 335 8 50 40 285 345 1085 845 270 300 9 50 45 280 345 1085 924 270 325 10 50 40 275 325 1125 968 270 360 11 60 30 270 335 1203 923 285 340 12 50 30 270 345 1100 956 280 320 13 60 25 275 340 1100 987 270 325 14 60 25 275 240 1165 967 270 320 15 50 35 275 345 1089 983 270 320 16 35 40 270 345 1124 925 265 320 17 40 40 275 350 1136 900 270 325 18 50 40 280 325 1185 901 285 320 19 50 45 280 335 1126 956 280 320 20 50 40 275 340 1065 945 270 335 Average 45.8 38.0 275.3 333.5 1090.3 926.4 275.3 326.5 Stan dev 8.93E+00 6.16E+00 4.72E+00 2.33E+01  6.10E+01 4.40E+01 6.17E+00 1.14E+01 T test 2.80E−03 2.67E−13 7.06E−12 5.81E−20 Probability % 99.72 100.00 100.00 100.00 % Difference −20.4 17.5 −17.7 15.7 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 8 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Zuma Sun Belt Zuma Sun Belt Zuma Sun Belt Zuma Sun Belt 1 50 20 285 325 800 800 270 295 2 35 20 265 300 856 852 270 290 3 45 25 275 300 795 698 270 285 4 45 25 270 330 725 654 275 300 5 40 25 270 320 898 678 280 300 6 40 20 270 310 865 752 280 325 7 40 25 275 305 785 632 280 310 8 45 30 285 300 742 752 275 295 9 45 30 275 300 765 786 275 290 10 50 25 270 300 726 720 285 305 11 45 30 270 305 856 725 270 300 12 45 35 260 310 736 698 270 315 13 40 30 270 295 754 621 270 305 14 40 30 270 305 865 715 275 300 15 40 25 275 290 842 728 275 300 16 40 20 270 300 798 719 275 295 17 35 25 270 300 897 690 270 300 18 35 25 275 310 800 735 275 315 19 40 30 275 300 758 748 275 290 20 40 35 280 295 795 714 270 285 Average 41.8 26.5 272.8 305.0 802.9 720.9 274.3 300.0 Stan dev 4.38E+00 4.62E+00 5.95E+00 1.01E+01 5.59E+01 5.47E+01 4.38E+00 1.04E+01 T test 4.75E−13 8.60E−15 3.45E−05 1.87E−12 Probability % 100.00 100.00 100.00 100.00 % Difference −57.5 10.6 −11.4 8.6 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 9 Core Length (mm) Plant Length (mm) Head Weight (g) Frame Diameter (mm) Sample # Zuma Sun Belt Zuma Sun Belt Zuma Sun Belt Zuma Sun Belt 1 60 65 275 295 856 654 275 325 2 50 60 280 295 845 625 270 300 3 55 55 280 280 878 724 270 300 4 55 50 285 305 825 765 270 310 5 55 50 285 300 814 805 270 315 6 60 65 285 300 798 723 270 300 7 45 65 285 305 800 654 275 285 8 45 65 285 310 765 628 270 295 9 40 50 265 295 745 648 275 280 10 40 50 275 280 825 659 285 315 11 55 65 285 310 748 756 280 300 12 55 60 275 285 854 698 270 300 13 55 60 275 290 825 741 270 285 14 55 55 270 285 816 721 275 290 15 50 50 275 280 900 695 275 305 16 55 65 275 285 865 632 270 325 17 45 50 280 275 879 754 270 310 18 45 65 275 300 894 798 285 295 19 50 60 270 310 805 654 265 280 20 55 65 270 325 831 669 270 315 Average 51.3 58.5 277.5 295.5 828.4 700.2 273.0 301.5 Stan dev 6.04E+00 6.51E+00 6.18E+00 1.31E+01 4.45E+01 5.68E+01 5.23E+00 1.36E+01 T test 7.84E−04 2.22E−06 1.33E−09 1.19E−10 Probability % 99.92 100.00 100.00 100.00 % Difference 12.4 6.1 −18.3 9.5 Confidence 0.042 0.040 0.042 0.047 0.042 0.047 0.042 0.047 Interval

TABLE 10 Results of the PCR Analysis to Determine Corky Root Resistance Corky Root Resistance based PCR analysis of individual plants Plant No. FIJI Mundaka Zuma Frontier Avalanche PRO 1432 1 Resistant Resistant Resistant Susceptible Resistant Resistant 2 Resistant Resistant Resistant Susceptible Resistant Resistant 3 Resistant Resistant Resistant Susceptible Resistant Resistant 4 Resistant Resistant Resistant Susceptible Resistant Resistant 5 Resistant Resistant Resistant Susceptible Resistant Resistant 6 Resistant Resistant Resistant Susceptible Resistant Susceptible 7 Resistant Resistant Resistant Susceptible Resistant Susceptible 8 Resistant Resistant Resistant Susceptible Resistant Susceptible 9 Resistant Resistant Resistant Susceptible Resistant Susceptible 10 Resistant Resistant Resistant Susceptible Resistant Susceptible

Table 10 shows that based on the PCR analysis for ‘cor’, Fiji, Mundaka, Zuma and Avalanche are all homozygous recessive for the ‘cor’ gene, making the varieties resistant to corky root. PCR tests were performed by California Seed Plant Laboratory, Elverta, Calif. Frontier is homozygous dominant for ‘cor’, and is susceptible to the disease. Based on this analysis, PRO 1432 is segregating for the resistance.

Resistance to Sclerotinia minor was determined by growing the test variety against known susceptible varieties in fields where S. minor is present, under climatical conditions where S. minor is known to thrive. Such conditions are when humidity levels are high and the average temperatures are between 55 and 65 degrees F. The test plots are made as equivalent as possible using standard field plotting techniques and resistance is defined by visible infection. The symptoms are rotting or decaying basal portions of the plant. There is no practical survival or partial infection to provide relative scoring. The plants are either infected and scored with a ‘1’ and die, or not infected and scored with a ‘0’. Results are shown in TABLES 11-13 and demonstrate that Fiji, Mundaka and Zuma are resistant to S. Minor.

TABLE 11 Mortality Mortality Mortality from from from Sclerotinia Sun Sclerotinia Sun Sclerotinia Sun Plant FIJI Belt Plant FIJI Belt Plant FIJI Belt 1 0 1 1 1 1 1 0 0 2 0 1 2 1 1 2 0 0 3 0 1 3 0 1 3 0 0 4 0 1 4 0 0 4 0 1 5 0 1 5 0 1 5 0 1 6 0 0 6 0 0 6 0 1 7 0 1 7 0 1 7 0 1 8 1 1 8 0 0 8 0 1 9 0 0 9 0 1 9 0 0 10 0 0 10 0 1 10 0 1 11 0 0 11 0 0 11 0 0 12 0 0 12 0 0 12 0 1 13 0 1 13 0 1 13 0 0 14 0 0 14 0 1 14 0 1 15 0 1 15 0 1 15 0 0 16 0 0 16 1 0 16 1 1 17 0 1 17 0 1 17 0 1 18 0 1 18 0 0 18 1 1 19 0 1 19 0 1 19 0 1 20 0 1 20 0 1 20 0 1 21 0 0 21 0 1 21 0 0 22 0 1 22 0 1 22 0 0 23 0 1 23 0 0 23 0 1 24 0 1 24 1 1 24 1 0 25 0 0 25 0 0 25 1 1 26 0 1 26 0 1 26 0 0 27 0 1 27 0 1 27 0 1 28 0 1 28 0 1 28 0 0 29 0 1 29 0 1 29 0 1 30 0 0 30 0 0 30 0 1 avg 0.03 0.67 avg 0.13 0.67 avg 0.13 0.6 std dev 0.18 0.48 std dev 0.35 0.48 std dev 3.46E−01 4.98E−01 ttest 7.36804E−09 ttest 6.93E−06 ttest 8.86E−05 probability 100.00 probability 100.00 probability 99.99 % 3.3 66.7 % 13.3 66.7 % 13.3 60.0 Mortality Mortality Mortality

TABLE 12 Mortality Mortality Mortality from from from Sclerotinia Sun Sclerotinia Sun Sclerotinia Sun Plant MUNDAKA Belt Plant MUNDAKA Belt Plant MUNDAKA Belt 1 0 1 1 0 1 1 0 0 2 0 1 2 0 1 2 0 0 3 0 1 3 0 1 3 0 0 4 0 1 4 0 0 4 0 1 5 0 1 5 0 1 5 0 1 6 0 0 6 1 0 6 0 1 7 0 1 7 0 1 7 0 1 8 0 1 8 0 0 8 0 1 9 0 0 9 1 1 9 0 0 10 1 0 10 0 1 10 0 1 11 0 0 11 0 0 11 0 0 12 0 0 12 0 0 12 0 1 13 0 1 13 0 1 13 0 0 14 1 0 14 0 1 14 0 1 15 0 1 15 0 1 15 1 0 16 0 0 16 0 0 16 0 1 17 0 1 17 0 1 17 0 1 18 0 1 18 0 0 18 0 1 19 0 1 19 0 1 19 0 1 20 0 1 20 1 1 20 0 1 21 0 0 21 0 1 21 0 0 22 0 1 22 0 1 22 0 0 23 0 1 23 0 0 23 0 1 24 0 1 24 0 1 24 1 0 25 0 0 25 0 0 25 0 1 26 0 1 26 0 1 26 0 0 27 0 1 27 0 1 27 0 1 28 0 1 28 0 1 28 0 0 29 0 1 29 0 1 29 0 1 30 0 0 30 0 0 30 0 1 avg 0.1 0.7 avg 0.1 0.67 avg 0.07 0.6 std dev 0.25 0.48 std dev 0.31 0.48 std dev 2.54E−01 5.16E−01 ttest 1.09205E−07 ttest 1.03E−06 ttest 2.48E−06 probability 100.00 probability 100.00 probability 100.00 % 6.7 66.7 % 10.0 66.7 % 6.7 60.0 Mortality Mortality Mortality

TABLE 13 Mortality Mortality Mortality from from from Sclerotinia Sun Sclerotinia Sun Sclerotinia Sun Plant ZUMA Belt Plant ZUMA Belt Plant ZUMA Belt 1 0 1 1 0 1 1 0 0 2 0 1 2 0 1 2 0 0 3 0 1 3 0 1 3 0 0 4 0 1 4 0 0 4 0 1 5 0 1 5 0 1 5 0 1 6 0 0 6 0 0 6 0 1 7 0 1 7 0 1 7 0 1 8 0 1 8 1 0 8 0 1 9 1 0 9 0 1 9 0 0 10 0 0 10 0 1 10 1 1 11 0 0 11 0 0 11 0 0 12 0 0 12 0 0 12 0 1 13 0 1 13 0 1 13 0 0 14 1 0 14 0 1 14 0 1 15 0 1 15 0 1 15 0 0 16 0 0 16 0 0 16 0 1 17 0 1 17 0 1 17 0 1 18 0 1 18 0 0 18 0 1 19 0 1 19 0 1 19 0 1 20 0 1 20 0 1 20 0 1 21 0 0 21 0 1 21 0 0 22 0 1 22 0 1 22 0 0 23 0 1 23 1 0 23 0 1 24 1 1 24 0 1 24 0 0 25 0 0 25 0 0 25 0 0 26 0 1 26 0 1 26 0 0 27 0 1 27 0 1 27 0 1 28 0 1 28 0 1 28 0 0 29 0 1 29 0 1 29 0 1 30 0 0 30 0 0 30 0 1 avg 0.1 0.7 avg 0.07 0.67 avg 0.03 0.6 std dev 0.31 0.48 std dev 0.25 0.48 std dev 1.83E−01 4.98E−01 ttest 1.03312E−06 ttest 1.09E−07 ttest 2.42E−07 probability 100.00 probability 100.00 probability 100.00 % 10.0 66.7 % 6.7 66.7 % 3.3 60.0 Mortality Mortality Mortality

Resistance was determined by growing the test varieties against known susceptible varieties in fields where TBSV is present. The test plots are made as equivalent as possible using standard field plotting techniques and resistance is defined by visible infection. Infected plants can be severely stunted and mature, diseased plants may only reach 6 to 8 inches in height. The outermost leaves are extensively yellowed. The younger, inner leaves often remain dark green in color, but can be rough and leathery in texture. In some cases, the older leaves develop necrotic spotting that can turn into extensive areas of brown, dead tissue. There is no partial infection to provide relative scoring. The plants are either infected and scored with a ‘1’ and die, or not infected and scored with a ‘0’.

TABLE 14 FIJI, MUNDAKA, ZUMA TBSV Resistance Mortality from Mortality from Tomato Bushy Stunt Tomato Bushy Stunt Plant FIJI Sun Belt Plant FIJI Sun Belt 1 0 1 1 0 1 2 0 1 2 0 1 3 0 1 3 0 1 4 0 0 4 0 1 5 0 0 5 0 1 6 1 0 6 0 1 7 0 1 7 0 1 8 0 1 8 0 1 9 0 1 9 0 1 10 0 1 10 0 0 11 0 1 11 1 0 12 0 0 12 1 0 13 0 0 13 0 1 14 0 0 14 0 1 15 0 1 15 0 1 16 0 0 16 0 1 17 0 1 17 0 0 18 0 1 18 0 1 19 0 1 19 0 1 20 0 1 20 0 1 21 0 1 21 0 0 22 0 0 22 0 1 23 0 0 23 0 0 24 0 1 24 1 1 25 0 1 25 0 1 26 0 1 26 0 0 27 0 1 27 0 1 28 0 1 28 0 1 29 0 0 29 0 1 30 0 1 30 0 1 avg 0.033333333 0.666666667 avg 0.1 0.766666667 std dev 0.182574186 0.479463301 std dev 0.305128577 0.430183067 ttest 7.36804E−09 ttest 3.94077E−09 probability 100.00 probability 100.00 % 3.3 66.7 % 10.0 76.7 Mortality Mortality

TABLE 15 Mortality from Mortality from Tomato Bushy Stunt Tomato Bushy Stunt Plant MUNDAKA Sun Belt Plant MUNDAKA Sun Belt 1 0 1 1 0 1 2 0 1 2 0 1 3 0 1 3 0 1 4 0 0 4 0 1 5 0 0 5 0 1 6 0 0 6 0 1 7 0 1 7 0 1 8 0 1 8 0 1 9 1 1 9 0 1 10 0 1 10 0 0 11 0 1 11 0 0 12 0 0 12 0 0 13 0 0 13 0 1 14 0 0 14 1 1 15 0 1 15 0 1 16 0 0 16 0 1 17 0 1 17 0 0 18 0 1 18 0 1 19 0 1 19 0 1 20 0 1 20 0 1 21 0 1 21 0 0 22 0 0 22 1 1 23 1 0 23 1 0 24 0 1 24 0 1 25 0 1 25 0 1 26 0 1 26 0 0 27 0 1 27 0 1 28 0 1 28 0 1 29 0 0 29 0 1 30 0 1 30 0 1 avg 0.066666667 0.666666667 avg 0.1 0.766666667 std dev 0.253708132 8.751925098 std dev 0.305128577 0.430183067 ttest 1.09205E−07 ttest 3.94077E−09 probability 100.00 probability 100.00 % 6.7 66.7 % 10.0 76.7 Mortality Mortality

TABLE 16 Mortality from Mortality from Tomato Bushy Stunt Tomato Bushy Stunt Plant ZUMA Sun Belt Plant ZUMA Sun Belt 1 0 1 1 1 1 2 0 1 2 0 1 3 0 1 3 0 1 4 0 0 4 0 1 5 0 0 5 0 1 6 0 0 6 0 1 7 0 1 7 0 1 8 0 1 8 0 1 9 0 1 9 0 1 10 0 1 10 0 0 11 1 1 11 0 0 12 0 0 12 0 0 13 0 0 13 0 1 14 0 0 14 0 1 15 0 1 15 1 1 16 1 0 16 0 1 17 0 1 17 0 0 18 0 1 18 0 1 19 0 1 19 0 1 20 0 1 20 0 1 21 0 1 21 0 0 22 0 0 22 0 1 23 0 0 23 0 0 24 0 1 24 0 1 25 0 1 25 0 1 26 0 1 26 0 0 27 0 1 27 0 1 28 0 1 28 0 1 29 0 0 29 0 1 30 0 1 30 0 1 avg 0.066666667 0.666666667 avg 0.066666667 0.766666667 std dev 0.253708132 8.652022533 std dev 0.253708132 0.430183067 ttest 1.09205E−07 ttest 2.88674E−10 probability 100.00 probability 100.00 % 6.7 66.7 % 6.7 76.7 Mortality Mortality

Although the foregoing invention has been described in some detail by way of illustration and examples for purposes of clarity and understanding, it will be obvious that certain modifications and alternative embodiments of the invention are contemplated which do not depart from the spirit and scope of the invention as defined by the foregoing teachings and appended claims. 

1. Lettuce seed designated as FIJI having ATCC Accession Number PTA-10855.
 2. A lettuce plant produced by growing the seed of claim
 1. 3. A lettuce head isolated from the plant of claim
 2. 4. A lettuce plant having all the physiological and morphological characteristics of the lettuce plant of claim
 2. 5. A F₁ hybrid lettuce plant having FIJI as a parent where FIJI is grown from the seed of claim
 1. 6. Pollen of the plant of claim
 2. 7. An ovule of the plant of claim
 2. 8. Tissue culture of the plant of claim
 2. 9. A method of selecting lettuce, comprising a) growing more than one plant from the seed of claim 1 b) selecting a plant from step a).
 10. A selected lettuce plant selected by the method of claim
 9. 11. A lettuce seed produced from the selected plant of claim
 10. 12. Lettuce seed designated as MUNDAKA having ATCC Accession Number PTA-10856.
 13. A lettuce plant produced by growing the seed of claim
 12. 14. A lettuce head isolated from the plant of claim
 13. 15. A lettuce plant having all the physiological and morphological characteristics of the lettuce plant of claim
 13. 16. A F₁ hybrid lettuce plant having MUNDAKA as a parent where MUNDAKA is grown from the seed of claim
 12. 17. Pollen of the plant of claim
 13. 18. An ovule of the plant of claim
 13. 19. Tissue culture of the plant of claim
 13. 20. A method of selecting lettuce, comprising a) growing more than one plant from the seed of claim 12 b) selecting a plant from step a).
 21. A selected lettuce plant selected by the method of claim
 20. 22. A lettuce seed produced from the selected plant of claim
 21. 23. Lettuce seed designated as ZUMA having ATCC Accession Number PTA-10857.
 24. A lettuce plant produced by growing the seed of claim
 23. 25. A lettuce head isolated from the plant of claim
 24. 26. A lettuce plant having all the physiological and morphological characteristics of the lettuce plant of claim
 24. 27. A F₁ hybrid lettuce plant having ZUMA as a parent where ZUMA is grown from the seed of claim
 23. 28. Pollen of the plant of claim
 24. 29. An ovule of the plant of claim
 24. 30. Tissue culture of the plant of claim
 24. 31. A method of selecting lettuce, comprising a) growing more than one plant from the seed of claim 23 b) selecting a plant from step a).
 32. A selected lettuce plant selected by the method of claim
 31. 33. A lettuce seed produced from the selected plant of claim
 32. 